IPv6: NLM_F_CREATE should be set when creating new route
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WARNING: CPU: 1 PID: 18459 at drivers/net/netdevsim/fib.c:831 nsim_fib6_event_init drivers/net/netdevsim/fib.c:831 [inline]
WARNING: CPU: 1 PID: 18459 at drivers/net/netdevsim/fib.c:831 nsim_fib6_prepare_event drivers/net/netdevsim/fib.c:947 [inline]
WARNING: CPU: 1 PID: 18459 at drivers/net/netdevsim/fib.c:831 nsim_fib_event_schedule_work drivers/net/netdevsim/fib.c:1003 [inline]
WARNING: CPU: 1 PID: 18459 at drivers/net/netdevsim/fib.c:831 nsim_fib_event_nb+0xb9d/0x10d0 drivers/net/netdevsim/fib.c:1043
Modules linked in:
CPU: 1 UID: 0 PID: 18459 Comm: syz.5.3737 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:nsim_fib6_event_init drivers/net/netdevsim/fib.c:831 [inline]
RIP: 0010:nsim_fib6_prepare_event drivers/net/netdevsim/fib.c:947 [inline]
RIP: 0010:nsim_fib_event_schedule_work drivers/net/netdevsim/fib.c:1003 [inline]
RIP: 0010:nsim_fib_event_nb+0xb9d/0x10d0 drivers/net/netdevsim/fib.c:1043
Code: 24 20 48 8b 6c 24 38 e8 e1 0c 91 fa e8 dc 0c 91 fa 89 de 44 89 ef e8 52 07 91 fa 41 39 dd 0f 84 cb fd ff ff e8 c4 0c 91 fa 90 <0f> 0b 90 e9 bd fd ff ff e8 b6 0c 91 fa 48 8d 7d 38 be 01 00 00 00
RSP: 0018:ffffc9001700f138 EFLAGS: 00010287
RAX: 000000000000ef33 RBX: 0000000000000001 RCX: ffffc9001e561000
RDX: 0000000000080000 RSI: ffffffff872a83cc RDI: 0000000000000004
RBP: ffff888052c16000 R08: 0000000000000004 R09: 0000000000000002
R10: 0000000000000001 R11: 0000000000000001 R12: ffffc9001700f290
R13: 0000000000000002 R14: ffff888034d4e300 R15: ffff888052a8b800
FS:  00007fdb710786c0(0000) GS:ffff8881247bd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002000 CR3: 0000000068c04000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85
 atomic_notifier_call_chain+0x71/0x1c0 kernel/notifier.c:223
 call_fib_notifiers+0x33/0x70 net/core/fib_notifier.c:35
 call_fib6_multipath_entry_notifiers+0x112/0x170 net/ipv6/ip6_fib.c:425
 ip6_route_multipath_add+0xb4f/0x1bd0 net/ipv6/route.c:5527
 inet6_rtm_newroute+0xe4/0x1a0 net/ipv6/route.c:5649
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6946
 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg net/socket.c:729 [inline]
 ____sys_sendmsg+0xa98/0xc70 net/socket.c:2614
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
 __sys_sendmsg+0x16d/0x220 net/socket.c:2700
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdb7018ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdb71078038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fdb703b5fa0 RCX: 00007fdb7018ebe9
RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000000000000003
RBP: 00007fdb70211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdb703b6038 R14: 00007fdb703b5fa0 R15: 00007fffa2097968
 </TASK>